P2RY13 and inborn error of immunity: Of note, in patients with high P2RY13 expression, a few immune-related pathways were identified, including ‘B cell receptor signaling pathway’, ‘T cell receptor signaling pathway’, ‘Intestinal immune network for IgA production’, ‘Natural killer cell-mediated cytotoxicity’, ‘Primary immunodeficiency’, ‘Chemokine signaling pathway’ and ‘Cytokine-Cytokine receptor interaction’ (Fig. 7B).